This application is related to Japanese Patent Application No. H11-237277, filed Aug. 24, 1999, the disclosure of which is hereby incorporated by reference in its entirety.
The present invention generally relates to components onto which a resin is molded, and more specifically, molding a resin body onto seat belt components such as a shoulder anchor, a tongue, and the like to lessen or eliminate burrs.
The outer surfaces of seat belt components that are touched by a person""s hand are typically molded out of a synthetic resin. At least a portion of the metal components may be covered by the resin.
FIGS. 6(a) and (b) are schematic sectional views illustrating the molding of a synthetic resin onto the outer surfaces of a metal plate by a conventional mold processing method. As shown in FIG. 6(a), a metal plate 3 is inserted into a cavity 4. Cavity 4 is created by the joining of metal molds 1 and 2. A synthetic resin is charged into the cavity 4 by an injection machine or the like. After the resin hardens and the metal molds are removed, a component composed of the metal plate 3 whose outer surfaces are covered with a synthetic resin molded body 5 is obtained, as shown in FIG. 6(b).
According to the above-mentioned conventional mold processing method, a relatively large burr 6 can be made because the synthetic resin flows along the outer surfaces of the plate 3. The burr is created along at least a partial length of the defining edge or outer boundary of the molded resin body. The burr 6 not only lessens the aesthetics of the component but also possibility generates a friction force when coming into contact with a seat belt and thereby at least partially obstructing the smooth motion of the seat belt.
An object of the present invention is to overcome the drawback caused by a burr formed by the molding process. The burr is lessened in size or eliminated by forming an externally standing step surface or surfaces on the metal portion, preferably near the end of the molded resin body.
In such a molded component, the stepped surfaces would prevent the flow of synthetic resin. However, the occurrence of a large burr and/or the occurrence of a burr that obstructs the smooth sliding of a seat belt can be prevented. Specifically, when the metal component is inserted into the metal molds and a resin is injected, the injection is carried out by abutting the stepped surfaces of the metal component against the inner surfaces of the metal molds, and the stepped surfaces are pressed against the metal molds by the pressure of the injected resin. Accordingly, no or a smaller gap is formed between the stepped surfaces and the inner surfaces of the metal molds and consequently no or a smaller burr is made.
The present invention is directed to overcoming or at least reducing some of the problems set forth above and at least is directed to accomplishing at least some of the objectives set forth above.